High-speed uplink packet access (HSUPA) technologies are introduced into a wideband code division multiple access (WCDMA) system and main characteristics of an HSUPA system include: (1) employing 10 ms/2 ms short frames; (2) employing a hybrid automatic repeat request (HARQ) in a physical layer; and (3) implementing fast scheduling on a User Equipment (UE) at a NodeB.
In the current HSUPA system, uplink multi-path search and channel estimation functions are mainly implemented relying on a DPCCH (Dedicated Physical Control Channel).
In practice, a power level of an uplink DPCCH channel is mainly decided by the parameters such as transmission block size, target retransmission times, a reference E-DCH transport format combination indicator (E-TFCI) and a reference power offset of an enhanced-dedicated physical data channel (E-DPDCH) relative to DPCCH, an HARQ PO (PO is short for power offset) of each media access control-d (MAC-d) flow, and the like. Because HSUPA supports variable speeds, all transmission blocks may be scheduled by a scheduling algorithm. In case of fixed target retransmission times, uplink DPCCH SIR levels corresponding to each transmission block at the moment are required closer to each other, in view of that speed of an outer loop power control (OLPC) algorithm on adjusting a signal to interference ratio (SIR) target value is far slower than change of the transmission blocks. However, the uplink DPCCH SIR level of each transmission block is mainly determined by such parameters as the target retransmission times, the reference E-TFCI and the reference power offset of the E-DPDCH relative to the DPCCH, the HARQ PO for each MAC-d flow, and the like. In the case of fixedly configured target retransmission times, the reference offset of the E-DPDCH relative to the DPCCH and the HARQ PO for each MAC-d flow are also fixedly configured.
Based on the existing protocol architecture, the power level of the uplink DPCCH is relatively stable in the case that the reference E-TFCI, the reference power offset and the HARQ PO are fixedly configured; and the power level of the uplink DPCCH cannot balance an uplink higher speed data transmission state with an uplink low-speed data transmission state simultaneously in the case that the target retransmission times are fixed. It should be noted that, except a WCDMA system, other communication systems such as a Long Term Evolution system may also encounter similar problems.